<h1>Validation</h1>

<h2>Rules for validation tasks</h2>

<p class="devnote">Explain Rule based system in skeleton. Strategy pattern</p>

<p>A standard interface are defined for rules to check if a condition is met and to provide an error message if it failed. Rules provide an isValid() method to check whether the rule passed or failed. A getErrorMsg() method gives access the error message if the rule failed. A Validator classe will run multiple rules to check an item in a container.</p>